01446678004 | Broad Street, Barry CF62 7AH | Open: Mon-Fri: 8:30 - 5:30pm Sat: 8:30 - 12:30pm Sun: Closed hello@ijpautomotive.co.uk

Wrong Fuel In Car or Van?

The moment you realise you’ve just filled, or started filling your car with the wrong fuel has got to be one of the most sickening feelings in owning a car. Feeling completely helpless isn’t uncommon, but if you follow some simple steps you can make sure you don’t cause any long term damage.

What To Do If You’ve Put Petrol In A Diesel Car or Van?

Firstly, don’t panic.

The situation is highly recoverable whilst you still have the pump in your hand.

Switch off the pump. Pay for your fuel and let the station attendant know that your car can’t be started.

Under no circumstance should you start your car, or even turn on the ignition fully. This may initiate the fuel primer pump which will start the process of pumping the fuel into the system.

Then you should call your breakdown service.


If you’re in Barry in the Vale of Glamorgan, IJP Automotive can drain the fuel for you with specialist equipment designed to be fast and effective, getting you back on the road in no time.

If that’s you – call us now on 01446678004

What Happens If You Put Petrol In A Diesel Car?

If you’ve filled your car with the wrong fuel, this means the fuel tank is contaminated with the wrong fuel – and at this moment, it is just the tank – great news. If you’ve managed to catch yourself at this point, the situation is easily recoverable, especially at a garage with the right equipment.

Just get someone to help you move to a safe place within the petrol station, without starting the engine – and call a breakdown service like the AA or a local garage near you.

If you’re in Barry Call IJP Automotive if you’ve put the wrong fuel in your car – 01446678004

What If I put Petrol In A Diesel Car by Mistake And Drove It?

Now then…

The situation gets a little more complicated if you’ve started to drive the car. At this point the mixture of fuels has started to make it’s way through the fuel system, into secondary pumps and fuel filters. At this point the whole system will need draining to some extent.

Once again this must be done with the right equipment and with modern high pressure fuel systems, if attempted using “old school” methods this can be EXTREMELY dangerous.

Petrol in a Diesel fuel tank is a very solvable problem with minimal cost – the tank can be drained without fuss.

Petrol in a Diesel engine however is a lot more extensive – the tank and fuel system will need to be flushed. This is essentially what happens when you fill up your diesel car with petrol and drive it.

What If There’s A Small Amount Of Petrol In Diesel Car?

There are those in-between occasions where you have contaminated only a small amount of fuel, for example you’ve pumped a litre or two into the tank.

How much petrol in diesel is safe?

It is possible to dilute the fuel you’ve already pumped by topping the tank up with the correct fuel. Despite diluting however, the seals and gaskets within your fuel system will behave differently, they are designed specifically for the correct fuel. The wrong fuel can cause them to swell or crack – particularly in higher concentrations, which can happen when the fuels separate.

Therefore, even if you think you can get away with it, it’s worth calling into a a garage with the correct equipment and having the fuel system flushed it may well save you a tonne of cash in fuel system repairs and seal or component replacements.

Putting Unleaded In A Diesel Car Is More Common Than You’d Think

Don’t beat yourself up about it if you have filled up with the wrong fuel. It’s amazingly common and easily done. Ignoring the problem and hoping things will be alright however will likely be a lot more embarrassing and costly.

If this is you right now, make the call to a fuel draining service, breakdown service, or local recovery service. If you’re in Barry in the Vale of Glamorgan call our breakdown service at IJP Automotive o 01446678004

Petrol In Diesel Car Symptoms

So you’re not sure whether you’ve filled up the car with the wrong fuel. You just know something doesn’t feel right with the car.

If you suspect it’s a possibility that you or your partner have filled the car up with the wrong fuel, it’s best to get to a local garage for them to diagnose the issue.

Make them aware that it could be a wrong fuel problem! Otherwise they could be chasing their tails trying to find a problem that doesn’t exist.

Symptoms you might expect of unleaded in a Diesel Car:

  • Louder than usual knocking when accelerating
  • Acceleration will be slower than usual
  • The exhaust may be a bit smokey
  • The car will be “rough” and “lumpy” when ticking over (your foot not on the accelerator)
  • Engine warning lights may come on in your dashboard
  • The engine might stop and simply won’t get started or stay running for very long (especially if the engine is warm)


What happens if I use the wrong fuel in my car?

Using the wrong fuel in your car can have various consequences, depending on the type of fuel used and the vehicle’s design. You can face performance problems, engine damage, fuel system issues, exhaust system problems, and expensive repairs.

How long does it take to fix wrong fuel in car?

The time it takes to fix a car after using the wrong fuel can vary depending on several factors, including the type of fuel used, the amount of wrong fuel introduced into the system, the vehicle’s make and model, and the extent of damage caused. If you suspect you’ve used the wrong fuel, it’s important to address the issue promptly to minimize potential damage to your vehicle and avoid costly repairs.

Can the wrong fuel cause engine failure?

Yes, using the wrong fuel in a vehicle can potentially lead to engine failure, especially if the incorrect fuel is used for an extended period or in large quantities.